So this made me think about the time I took a 3 port circulator apart. For those that are not familiar with circulators, the work like this:Put power in port 1 and it comes out port 2, put it in 2 and it comes out 3, put it in 3 and it comes out 1. All with out much loss. But if you try to go backwards, say 3 to 2, you loose 99% of the power.

Cool little device. So when I take it apart all it is is a flat triangle of copper, 2 triangle shaped pieces of ferrite, and a magnet.

If you don't know the math behind it, is looks at first blush as "silly" as the emdrive. No way could it do that. But it does. This thing may well work, we just don't know the math.

I'm an Engineer and I've studied the Polarizable Vacuum Model of General Relativity. What it would say is the following;

As a waveguide, the group velocity is something like;

v_g = c x sqrt(1 - (c/2d*f)^2)

Where, c is the usual speed of light, d is the diameter of the cylinder, and f is the frequency of the microwave excitation.

c/2d = fc, is the Low cut-off frequency of the waveguide.

The refractive index depends on the Low cut-off frequency as a function of the diameter,

K = 1/sqrt( 1 - (fc/f)^2)

For f >> fc, K~1. But for frequencies in the band fc1 < f <~ fc2, K is much larger.

There is a strong gradient in the refractive index from one end of the cone to the other. This "mimics" gravity, as interpreted in the PV Model.

Therefore, we can assume there is a "gravitational" gradient in the microwave band refractive index, along the length of the cone. At one end they have diameter d1, and at the other end they have diameter d2, and d1 > d2. Below fc1, the mode frequencies exponentially decay to zero. Just like the Casimir effect.

Here is how it conserves momentum;

In the PV Model, momentum transforms as,

p => p*sqrt(K)

In a resonant cavity, p is the SUM of all the photons “in phase", minus the losses of the cavity.

However, as photons “fall” from the large end toward the small end, they gain momentum, which is passed on to the cone when they are reflected from the small end. The photon then loses momentum as it travels back to the large end, where it imparts “less” momentum to the large end. The result is a NET propulsion in the direction of the small end. In other words, the photons are blue-shifted falling forward, and red-shifted going backwards, due to the gradient in the refractive index. It is literally gravitational red & blue shift, according to the PV Model.

The interesting thing is, the refractive index in the waveguide does not depend on the power of the microwaves, or the energy density. It is simply a matter of the geometry and frequency band relative to the cut-off. What matters more, is having enough resonant momentum stored to make the effect noticeable.

Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.

When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.

(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,

p => p*sqrt(K)

THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.

When I drop a brick it falls to the earth. But the earth also falls toward it. True, by only a tiny amount but multiplied by the huge mass of the earth and it gains as much momentum as the brick and in the opposite direction.

Did you really think that orbital mechanics did not conserve momentum?

Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.

When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.

(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,

p => p*sqrt(K)

THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.

Regards,Todd D.

Gravity certainly conserves momentum.

When I drop a brick it falls to the earth. But the earth also falls toward it. True, by only a tiny amount but multiplied by the huge mass of the earth and it gains as much momentum as the brick and in the opposite direction.

Did you really think that orbital mechanics did not conserve momentum?

You are referring to Newtonian gravity. I'm referring to a form of GR, where it is the curvature of the manifold intersecting the object that causes it to fall, not some "action at a distance" or exchange of gravitons. In this case, that curvature is simply the gradient in the refractive index. Inside the cone, photons are moving in a variable refractive index. This causes red & blue shift and an imbalance in momentum. This is exactly what the Earth does to the vacuum surrounding it, it filters field modes and that causes the refractive index to increase. The cone is like the falling object, falling relative to the imbalance in the internal momentum which is the curved manifold.

I agree, this is not standard GR, it is certainly not accepted physics. It is based on my own understanding of the Polarizable Vacuum Model of GR which I referenced earlier, as well as the Quantum Vacuum by Milonni, and my own work. Which predicted some 10 years ago, that it is easier to mimic gravity in over a limited bandwidth, than it is to create artificial gravity that affects all frequencies of light and matter.

Treat the device as a black box. I don't know or care what is happening inside it. At time T0 it has no momentum. Turn it on and let it accelerate so that it has some velocity and so momentum at time T1. Unless you can point to something with the same amount of momentum going in the other direction then by definition you have violated conservation of momentum. What happens inside the box simple does not affect that fact.

When you drop an object and it falls to the ground. Relative to you, it gained momentum from the gravitational field. It did not expel any propellant to fall. The gravitational field is simply a gradient in the refractive index of the vacuum surrounding the Earth. If you can explain conservation of momentum for falling objects in a gravitational field, then you have your answer.

(Edit) In other words, if the cavity were not tapered, then you have equal momentum inside traveling left and right. At T0, it will go nowhere. However, because it is tapered such that you have a gradient in the refractive index, then "just like gravity", photons will be blue shifted moving into higher K, and red shifted moving into lower K, because momentum,

p => p*sqrt(K)

THIS is a violation of conservation of momentum. Therefore, the cavity must move to conserve momentum, as it tries to establish equilibrium with it's own internal stress.

Regards,Todd D.

Gravity certainly conserves momentum.

When I drop a brick it falls to the earth. But the earth also falls toward it. True, by only a tiny amount but multiplied by the huge mass of the earth and it gains as much momentum as the brick and in the opposite direction.

Did you really think that orbital mechanics did not conserve momentum?

You are referring to Newtonian gravity. I'm referring to a form of GR, where it is the curvature of the manifold intersecting the object that causes it to fall, not some "action at a distance" or exchange of gravitons. In this case, that curvature is simply the gradient in the refractive index. Inside the cone, photons are moving in a variable refractive index. This causes red & blue shift and an imbalance in momentum. This is exactly what the Earth does to the vacuum surrounding it, it filters field modes and that causes the refractive index to increase. The cone is like the falling object, falling relative to the imbalance in the internal momentum which is the curved manifold.

I agree, this is not standard GR, it is certainly not accepted physics. It is based on my own understanding of the Polarizable Vacuum Model of GR which I referenced earlier, as well as the Quantum Vacuum by Milonni, and my own work. Which predicted some 10 years ago, that it is easier to mimic gravity in over a limited bandwidth, than it is to create artificial gravity that affects all frequencies of light and matter.

Todd D.

Sorry dude but that's just word salad. Momentum cannot "imbalance", GR is simply not relevant and if you have a black box that has gained momentum then you have to point to another object that has equal momentum in the other direction or you have violated conservation of momentum. By definition. If your version of GR allows this then your version of GR violates conservation of momentum.

EM drive is a very clear case of pseudoscience. Not because it contradicts physics, as we know it. Questioning current science is a normal scientific endeavour - provided that the questioner knows what he/she is doing. It is pseudoscience because of the double-talk about acceptance, or non-acceptance, of the "usual" physics.

Chris' article explains that the EM drive supposedly exchanges momentum with the so called "Quantum Vacuum". The well-established physics knows absolutely nothing about this possibility. That is, they propose existence of a completely new physical phenomenon, which may, or may not exist. (Probably not.) However, look this site:http://emdrive.com/principle.htmlHere they explain EM drive without the slightest mention of the revolution they propose in physics. The attached theory paper makes specific calculations about the operation of the drive, apparently on the basis of the usual physics. Again, there is no mention of a momentum exchange with the "Quantum Vacuum". Chris' paper mentions also a "new computational code that models the EM Drive’s thrust". Again, this implies that their thinking is based on a known theory, instead of some speculation about a currently unknown phenomenon.

So, do they revolutionize physics? Or, they just apply the existing ones? In the first case, how can they make calculations without developing the quantum theory of their alleged momentum exchange to "Quantum Vacuum"? There is no such thing in their their theory paper. In the second case, momentum conservation prohibits EM drive to work and they calculations must be wrong. Momentum conservation is not something optional: Within the framework of the known quantum physics, momentum conservation is a direct consequence of translation invariance. You cannot tamper it without questioning the very basics of quantum physics.

EM drive is a very clear case of pseudoscience. Not because it contradicts physics, as we know it. Questioning current science is a normal scientific endeavour - provided that the questioner knows what he/she is doing. It is pseudoscience because of the double-talk about acceptance, or non-acceptance, of the "usual" physics.

Chris' article explains that the EM drive supposedly exchanges momentum with the so called "Quantum Vacuum". The well-established physics knows absolutely nothing about this possibility. That is, they propose existence of a completely new physical phenomenon, which may, or may not exist. (Probably not.) However, look this site:http://emdrive.com/principle.htmlHere they explain EM drive without the slightest mention of the revolution they propose in physics. The attached theory paper makes specific calculations about the operation of the drive, apparently on the basis of the usual physics. Again, there is no mention of a momentum exchange with the "Quantum Vacuum". Chris' paper mentions also a "new computational code that models the EM Drive’s thrust". Again, this implies that their thinking is based on a known theory, instead of some speculation about a currently unknown phenomenon.

So, do they revolutionize physics? Or, they just apply the existing ones? In the first case, how can they make calculations without developing the quantum theory of their alleged momentum exchange to "Quantum Vacuum"? There is no such thing in their their theory paper. In the second case, momentum conservation prohibits EM drive to work and they calculations must be wrong. Momentum conservation is not something optional: Within the framework of the known quantum physics, momentum conservation is a direct consequence of translation invariance. You cannot tamper it without questioning the very basics of quantum physics.

It is pseudoscience.

Use of the QV as a momentum dump is a idea from Dr. White of Eagleworks (a part of NASA).

Roger Shawyer, inventor of the EM Drive, claims there is no need for the QV and it is not involved.

Logged

"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”Herman Melville, Moby Dick

EM drive is a very clear case of pseudoscience. Not because it contradicts physics, as we know it. Questioning current science is a normal scientific endeavour - provided that the questioner knows what he/she is doing. It is pseudoscience because of the double-talk about acceptance, or non-acceptance, of the "usual" physics.

Chris' article explains that the EM drive supposedly exchanges momentum with the so called "Quantum Vacuum". The well-established physics knows absolutely nothing about this possibility. That is, they propose existence of a completely new physical phenomenon, which may, or may not exist. (Probably not.) However, look this site:http://emdrive.com/principle.htmlHere they explain EM drive without the slightest mention of the revolution they propose in physics. The attached theory paper makes specific calculations about the operation of the drive, apparently on the basis of the usual physics. Again, there is no mention of a momentum exchange with the "Quantum Vacuum". Chris' paper mentions also a "new computational code that models the EM Drive’s thrust". Again, this implies that their thinking is based on a known theory, instead of some speculation about a currently unknown phenomenon.

So, do they revolutionize physics? Or, they just apply the existing ones? In the first case, how can they make calculations without developing the quantum theory of their alleged momentum exchange to "Quantum Vacuum"? There is no such thing in their their theory paper. In the second case, momentum conservation prohibits EM drive to work and they calculations must be wrong. Momentum conservation is not something optional: Within the framework of the known quantum physics, momentum conservation is a direct consequence of translation invariance. You cannot tamper it without questioning the very basics of quantum physics.

It is pseudoscience.

Casimir momentum is old news:

Here's some lectures to read. Make sure you follow up with the rest of the supporting materials going back 60+ years.

The theory papers out there are clearly not the issue to debate here. The device producing anomalous thrust is the issue here. Anybody can come up with a bunk theory. The Emdrive is still a black box deserving expert attention.

Everybody assumes that this thing is acting like a quantum rocket (and taking all sorts of liberties with established science to justify that), based off what I see, it is a sail.

This thrust should not exist according to physics, as we know it. An unquestionable experimental result would mean a scientific revolution. Still, people who allegedly measure this force calculate it as if it were a consequence of known physics. Something is wrong here.

Notwithstanding the known-objections to the proposed theoretical explanations (already pointed out in the article), the challenge has been to show whether the measurements are an experimental artifact or whether there is anything useful here for space propulsion.

Thanks for the answer Chris. My applogies, I should have been more specific, I meant the one that's labled 'Warpstar 1' and looks (probably more accurately) like the main cabin of the Fireball XL5. Sorry for the confusion.

The picture of "Warpstar 1"

was posted by Paul March (an engineer at NASA Eagleworks) in the EM Drive thread

I have no doubt now that this quantum vacuum derived propulsion system will be able to meet and ultimately surpass my conjectured WarpStar-I concept vehicle performance that I wrote about in my STAIF-2007 paper based on Woodward's Mach Lorentz Thrusters (MLT) of the day. A vehicle that could go from the surface of the Earth to the surface of the Moon with a crew of two and six passengers with luggage in under four hours and then return to the surface of the Earth in another 4 hours with the same payload using just one load of H2/O2 fuel cell derived electrical power assuming 500-to-1,000 N/kWe efficiency MLTs or Q-Thrusters. And yes, I know that's a mighty big leap from the 1.0uN/Watt we currently have demonstrated at the Eagleworks Lab, but if Dr. White's QVF/MHD conjecture is anywhere close to reality, it will be doable, at least in the long term.

Best, Paul M.

Note that Paul's statement

" I know that's a mighty big leap from the 1.0uN/Watt we currently have demonstrated at the Eagleworks Lab"

refers to the measured force in a vacuum per input electric power at NASA Eagleworks. The highest measured force per input power was 1 Newton/kiloWatt for the experiments by Prof. Yang in China with a non-superconducting truncated cone EM Drive and by Cannae LLC in the USA for their superconducting EM Drive shaped like a pillbox.

Just going through this information. I ignored the thread for several months thinking it was nonsense, but obviously it's worth looking at in more detail. If it it true, then it could be the biggest breakthrough since the man made motion from heat (I guess the steam engine).

However, I remain sceptical - and this doesn't help (sorry if this is dissected elsewhere):- 28 tons to the moon, assuming 60MJ/kg (100% efficient) requires 1.68E12 Joules- Enthalpy of formation of water = 285KJ/mol = 15.83E9 J/ton- Assuming 100% chemical to Gravitational energy, we need 1.68E12/15.83E9 tons = 106 tons. ONE WAY.

So the vehicle above breaks the laws of conservation of energy and could be used as a perpetual motion machine.

I can accept an incredible static thrust level, but not a breaking of this law.

The figure of 1W providing 30N implies that the reaction mass, whatever it is, is moving at 2m/s. That's a very slow exhaust.

However, you might be able to take a ballistic missile submarine, replace the missiles with this drive, and put your nuclear submarine in orbit - over the course of a few weeks (and ignoring the fact that the reactor won't work without cooling water).

EM drive is a very clear case of pseudoscience. ...................................................It is pseudoscience.

Personally, I'd wait till begin July, when Eagleworks perform their high power test, before making any such bold statements. It is not because theoretical physicists and aeronautic engineers are unable to formulate a coherent theory on something that might or might not work that it doesn't carry any value.

With such an attitude of dismissal, scientific research would simply get no where. Curiosity and investigation are the key elements for science, so... until the experiments are validated (positively or negatively) by several different parties, in a scientific manner, there is currently absolutely nothing substantial to be said, except for personal opinions and theories that address the "why?" question.

At this stage, there is no flawless proof for it to work, but neither has it been disproved. The only real constructive discussions are those that concerns possible flaws and shortcomings in current and past experiments, as they help to improve the next tests...The end goal is to assess whether or not the experiment shows enough scientific evidence for a definitive conclusion.

The theory papers out there are clearly not the issue to debate here. The device producing anomalous thrust is the issue here. Anybody can come up with a bunk theory. The Emdrive is still a black box deserving expert attention.

Everybody assumes that this thing is acting like a quantum rocket (and taking all sorts of liberties with established science to justify that), based off what I see, it is a sail.

1) if I put 50 watts into the drive and can't account for where even 1 micro watt goes, you can't just say it disappears. If it goes into work in the form of motive force, I don't see the violation here.

And the China tests at 2.45 (2.457 seemed to be peak) with a dirty source and they got a lot of thrust as well.

There is something known that could explain why A produced more thrust than B. It would also explain why D failed to produce thrust, resonator not withstanding, while the others did. It would also in my mind validate Dr. White's theory, or at least show he is going in the right direction.

I'll go into detail after Star-Drive's next log in just incase he would like me to keep my big fat mouth shut.

For those interested this has now reached the hallowed halls of Forbes who have taken an understandable very cautious approach. Actually the article could be interpreted as yet another in the line of it sounds too good to be true.

The theory papers out there are clearly not the issue to debate here. The device producing anomalous thrust is the issue here. Anybody can come up with a bunk theory. The Emdrive is still a black box deserving expert attention.

Everybody assumes that this thing is acting like a quantum rocket (and taking all sorts of liberties with established science to justify that), based off what I see, it is a sail.

A sail in what medium?

Nothing. Momentum from nothing.

There is actually real science here. You have to let go of your preconceptions first, and only stick to the facts.

(I see the original post was deleted by the person making it.....but the below still stands).

Some of these big "general interest" sites only want your clicks for their mass of advertisers, so basically one is patting them on the back by linking them. I always felt linking is not unlike liking. I know it'll always happen, but I don't think (X mass media site) will lose any sleep over criticism of their articles. I would also point out that big sites that are late to the game (as they are) tend to use an armwavey attitude via being upset they missed the boat on the considerable interest (both for and against) on this news. I assume that is the case before even reading it.

As far as bad reporting of content on this site, nothing we can do about that. They did link the article, so anyone who doesn't click through and read our article is doing themselves a disservice.

Moving on.....

PS A writer with a big site has got in touch and clearly is on the right side of the media, so we'll help him!